hook debug printing in OoT debug rom

Lua/inject.lua

@@ -23,6 +23,12 @@ local injection_points = {
         ow_addr = 0x0A19C8,
         ow_before = 0x0C0283EE,
     },
+    ['O EUDB MQ'] = {
+        inject_addr = 0x700000,
+        inject_maxlen = 0x100000,
+        ow_addr = 0x0C6940,
+        ow_before = 0x0C03151F,
+    },
 }
 
 local header = [[
@@ -89,10 +95,13 @@ function inject(fn)
     assemble(asm_path, write, {unsafe=true, offset=true_offset + length})
 
     printf("length: %i words", length/4)
+    --[[
+    -- FIXME: this only works properly when the asm doesn't use any .orgs
     if length > inject_maxlen then
         print("Assembly too large!")
         return
     end
+    --]]
 
     for pos, val in pairs(inject_bytes) do
         W1(pos, val)
@@ -114,7 +123,11 @@ function inject(fn)
 end
 
 if oot then
-    inject('spawn oot.asm')
+    if version == 'O EUDB MQ' then
+        inject('print.asm')
+    else
+        inject('spawn oot.asm')
+    end
 else
     if version == 'M JP10' or version == 'M JP11' then
         inject('spawn mm early.asm')

Lua/inject/print.asm

@@ -0,0 +1,40 @@
+// translates calls to 800021F8
+// to copy strings to memory instead
+// for Lua to later pick up on
+
+// reset buffer position in our per-frame hook
+    la      t0, buffer
+    sw      t0, buffer_pos
+// and set the string to null
+    sb      r0, 0(t0)
+    jr
+    nop
+
+// keep track of where we are in the buffer
+buffer_pos:
+    .word 0
+
+// set up 2048 bytes of text buffer
+// each line is 32 words, or 128 bytes
+// i don't think this is enough, actually
+.align 8
+buffer:
+    .word 0
+
+// overwrite (not hook) the debug printing function
+.org 0x800021B0
+    // a0: unknown
+    // a1: char *msg
+    // a2: size_t len
+    lw      t0, buffer_pos
+copy_loop:
+    lb      t1, 0(a1)
+    sb      t1, 0(t0)
+    addi    t0, t0, 1
+    addi    a1, a1, 1
+    subi    a2, a2, 1
+    bne     a2, r0, copy_loop
+    sb      r0, 0(t0) // null terminate
+    sw      t0, buffer_pos
+    jr
+    nop

Lua/print.lua

@@ -0,0 +1,31 @@
+require = require "depend"
+require "boilerplate"
+
+local buffer = 0x700070
+
+local vfc = A(0x168960, 4)
+
+while true do
+    local pos = buffer
+    local str = ''
+    while true do
+        local b = R1(pos)
+        pos = pos + 1
+        if b == 0 then
+            break
+        end
+        if b < 0x80 then
+            str = str..string.char(b)
+        else
+            str = str..'?'
+        end
+    end
+    print(str)
+    local old = vfc()
+    for i=1,30 do
+        emu.frameadvance()
+        local new = vfc()
+        if new ~= old then break end
+    end
+    console.clear() -- delete this if you want
+end